New Architecture: Folly header errors due to manual compiler flags before install_modules_dependencies

[ChrisWiles]

Issue

The session replay package (@datadog/mobile-react-native-session-replay v2.12.1) manually sets Folly compiler flags BEFORE calling install_modules_dependencies, causing build errors with React Native 0.81's precompiled XCFrameworks.

Error

'folly/coro/Coroutine.h' file not found

Current Code

if ENV['RCT_NEW_ARCH_ENABLED'] == '1' then
  s.compiler_flags = folly_compiler_flags + " -DRCT_NEW_ARCH_ENABLED=1"  # <- Manual Folly flags
  xcconfig.merge!({
    "DEFINES_MODULE" => "YES",
    "CLANG_CXX_LANGUAGE_STANDARD" => "c++17"
  })
end

s.pod_target_xcconfig = xcconfig

if respond_to?(:install_modules_dependencies, true)
  install_modules_dependencies(s)  # <- Called AFTER manual flags
end

Problem

In React Native 0.81, iOS dependencies ship as precompiled XCFrameworks and install_modules_dependencies handles all New Architecture setup automatically. Manually setting folly_compiler_flags before calling it causes conflicts because those Folly headers don't exist in the precompiled setup.

Fix

Let install_modules_dependencies handle everything when available:

if respond_to?(:install_modules_dependencies, true)
  install_modules_dependencies(s)
  if ENV['RCT_NEW_ARCH_ENABLED'] == '1' then
    xcconfig.merge!({
      "DEFINES_MODULE" => "YES"
    })
  end
else
  # Fallback for older RN versions
  if ENV['RCT_NEW_ARCH_ENABLED'] == '1' then
    s.compiler_flags = folly_compiler_flags + " -DRCT_NEW_ARCH_ENABLED=1"
    xcconfig.merge!({
      "DEFINES_MODULE" => "YES",
      "CLANG_CXX_LANGUAGE_STANDARD" => "c++17"
    })
  end
end

s.pod_target_xcconfig = xcconfig

Environment

• Package: @datadog/mobile-react-native-session-replay@2.12.1
• React Native: 0.81.4
• Expo SDK: 54
• Platform: iOS (EAS Build)

[marco-saia-datadog]

Hello @ChrisWiles 👋

Thank you for your feedback!

We have already fixed this issue with #993, and we are going to release it today with v2.12.2.

However, we will look into your suggested approach and test its compatibility with all supported RN versions.

[marco-saia-datadog]

👋 We have released v2.12.2, which contains the fix for this issue.